This proposal is directed toward a simple and systematic approach to the development of nonthrombogenic surfaces using presently available materials and evaluating the new systems in experimental animals. Biologically active agents will be combined with polymers and are capable of stimulating intracellular levels of cyclic adenosine monophosphate (cAMP). Slow release of the agents affect platelet function at the interface preventing platelet adhesion and interfacial induced thrombosis. The rationale of the proposal is based on interfacial biochemistry, pharmacological effects on platelet function, and preliminary data supporting the proposed methods. It was found that prostaglandins combined with commercially available polymers to from dispersed monolithic systems can provide controlled release of the agents of various rates for extended periods of time. Prostaglandins released from the polymer matrix have been found to be pharmacologically active by inhibiting platelet aggregation and significantly reducing platelet adhesion onto the polymer surface.